This invention relates to the field of food processing, and more particularly, to apparatus and methods for peeling vegetables and fruits.
It is common in many food processing applications to require the peeling of the outer skin of fruits or vegetables. Potatoes, in particular, are very often so processed by passing the potatoes against a set of rotating abrasive rollers. Fruit may also be similarly processed. For example, U.S. Pat. No. 2,605,798 to Boswell discloses a citrus fruit peeler including a pair of abrading rollers and an auger screw which advances the citrus along the rollers.
Along these lines, U.S. Pat. No. 3,745,914 to Wallace discloses a single chamber fruit and vegetable peeler including a frame, a plurality of abrasive roller carried by the frame and arranged in an arcuate pattern, and a drive motor and gears coupled to the rollers. The abrasive rollers are provided in lengthwise segments to facilitate replacement of a damaged section without requiring replacement of an entire roller. Action of the rollers advances the fruit or vegetables from an intake to a discharge. A rinsing system is provided to wash material from the rollers. The vegetables or fruit are subjected to a tumbling action within the peeling chamber. The amount of peeling is controlled by a height of a gate at the discharge.
U.S. Pat. No. 4,519,305 to Vanosdall discloses a similar apparatus wherein an auger extends only partway into the chamber from the discharge. U.S. Pat. No. 5,858,429 also to Wallace discloses a similar apparatus which includes an auger at a feed hopper, and a rotatable tumbler including rotating paddles within the peeling chamber. This patent also discloses a vision analysis system to evaluate the degree of peeling and adjust the various parameters to provide a desired degree of peeling.
U.S. Pat. No. 4,237,782 to Bichel and U.S. Pat. No. 4,827,836 to Neidigh disclose peeling apparatus wherein the abrasive rollers are driven by individual hydraulic motors. U.S. Pat. No. 5,780,088 to Zittel discloses a peeler that includes individual electric motors to drive each roller. The rollers can be operated at different speeds or in different directions. An auger which extends through the peeling chamber, may also be controlled by an electric motor.
To increase capacity, a dual peeling or washing chamber apparatus was offered by Vanmark Corporation under the model designation Series 2800. The apparatus included two side-by-side chambers wherein the augers rotated in a same direction. Accordingly, the abrasive rollers and their associated motors extended around an arc further upward on a same side.
Unfortunately, it may be difficult to manually control the various operating parameters of a typical peeling apparatus to obtain consistent results. This may be so particularly where the feed rate is difficult to control and/or the fruit or vegetables vary in size, shape and skin thickness. Vision-based feedback control systems may be relatively expensive and complicated to adjust for correct and consistent operation.
In view of the foregoing background, it is therefore an object of the invention to provide a peeling apparatus and associated methods which provide for efficient and effective control of the peeling operation.
This and other objects, features and advantages in accordance with the present invention are provided by a peeling apparatus comprising a set of abrasive rollers, at least one roller drive motor, a feeder for controllably feeding fruit or vegetables adjacent the abrasive rollers, at least one sensor associated with at least one roller drive motor for sensing a load thereon, and a controller for controlling the feeder based upon the at least one sensor. Accordingly, the feeder can be controlled based upon the sensed load on the abrasive rollers.
The controller may increase the feed rate of the feeder based upon an increase in sensed load, and conversely decrease the feed rate based upon a decrease in sensed load. In some embodiments, the controller may also control at least one roller drive motor of the set based upon the sensed load. The invention provides a relatively straightforward, robust and cost effective approach to control important peeling parameters.
The feeder may comprise an input conveyor upstream of the set of abrasive rollers. In addition to or in place of the input conveyor, the feeder may include an auger adjacent the set of abrasive rollers. Also, the feeder may include at least one of an intake gate and a discharge gate, with or without the input conveyor and/or auger.
The at least one sensor may comprise a torque sensor for sensing a torque delivered by the at least one roller drive motor. The roller drive motor may be a hydraulic motor, and the sensor may sense hydraulic pressure.
In one particularly advantageous class of embodiments, the at least one roller drive motor may comprise at least one roller drive electric motor. Accordingly, the at least one torque sensor may thus comprise at least one electrical power sensor.
In some embodiments, the at least one roller drive electric motor may comprise a respective roller drive electric motor for each abrasive roller. In these embodiments, the load on only one or more motors for the lower abrasive rollers may need to be sensed.
A method aspect of the invention is for operating a peeling apparatus of a type comprising a set of abrasive rollers, at least one roller drive motor, and a feeder. The method may comprise sensing a load on at least one roller drive motor, and controlling a feed rate of the feeder based upon the sensed load.